The present invention relates to an improved switch structure and to a technique for calibrating or "zeroing" the switch during manufacture. The switch is of the type that responds to changes in an environmental parameter (e.g., temperature). The most common variety of such a switch, of course, is a thermostatic switch incorporating a bimetallic member that moves in response to temperature changes to open and/or close the switch contacts. Such switches typically include a stop member disposed to abut the bimetallic arm at a predetermined orientation of that arm, thereby determining the temperature at which contact is made, or broken, by movement of the bimetallic arm.
In the manufacture of such switches, the positioning of such a stop member has traditionally been accomplished by a time-consuming, and expensive, manual setting of a mechanical adjustment. An additional difficulty with this prior calibration technique is that it is dependent upon the skill and/or attentiveness of the worker, thereby rendering suspect the uniformity of calibration between switches calibrated by different workers.
In view of the above discussion, it is a principal object of the present invention to provide an improved switch structure, and a technique of switch calibration, which eliminates the need for manual calibration of such switches. It is an additional object to provide such a switch, and such a technique, which are conducive to improved uniformity of calibration, improved speed of manufacture, and reduced expense of manufacture.